Buster points are used for breaking up solid material such as asphalt, concrete, and solidified metals. Small buster points which are approximately twenty-four inches in length are used in jack hammers. Large buster points having lengths up to eight feet are installed on large road-working equipment for such applications as bridge and road demolition. Buster points are also used in the steel industry for breaking residue off ladles and troughs.
Commercially available buster points are manufactured to a unibody construction and comprise a tip integrally connected to a long shaft. The tips of the buster points can dull fairly easily through field application due, in large part, to the great amount of force associated with breaking up dense materials. Historically, upon dulling of the tip, the buster point is either scrapped, or the entire buster point is forwarded to a blacksmith for rebuilding. Both of these scenarios are very expensive. In the first case, a total loss of the product occurs. In the second case, the user must pay to ship the buster point as well pay the blacksmith for extensive repair and rebuilding of the buster point.
Prior art buster point assemblies have also been manufactured as illustrated in FIGS. 1 through 5. These assemblies include a shaft, a replaceable tip, and a connector. The replaceable tip is fixedly attached to the shaft using the connector. The shaft includes a proximal end and a distal end. The proximal end serves as the drive end. Accordingly, the proximal end includes a means for connecting the shaft to a drill mechanism. A chamber is bored into the shaft at the distal end. The chamber is adapted to receive the replaceable tip. An aperture is also bored through the shaft. The aperture includes threads for receiving the connector.
The replaceable tip includes a working end and a connecting end. The working end is designed to break up solid material. The connecting end is adapted to fit within the chamber located at the distal end of the shaft. The connecting end includes a tapered section. In operation, the connector fits within the tapered section to fixedly attach the replaceable tip to the shaft.
The drawback of this prior art assembly is that bearing surface between the replaceable tip and the shaft can be damaged as the buster point pounds against very dense, solid objects. For example, the bearing surface can become spalled or bent by the constant pounding. Consequently, the replaceable tip could become difficult or impossible to remove from the shaft. Thus, the entire assembly would have to be replaced, rather than the less expensive replaceable tip.
The present invention is provided to solve these and other problems.